const version = require("element-ui/package.json").version;//获取版本号
const ORIGINAL_THEME = "#409EFF";//主题默认色
const colorAngle = 20;//颜色差 越大越亮 越小越暗
const colorAngleS = -40;//颜色差 越大越亮 越小越暗
export const Colors = {
    updateStyle:function (style, oldCluster, newCluster) {
        let newStyle = style;
        oldCluster.forEach((color, index) => {
            newStyle = newStyle.replace(new RegExp(color, "ig"), newCluster[index]);
        });
        return newStyle;
    },
    getCSSString:function(url, callback, variable) {
        const xhr = new XMLHttpRequest();
        xhr.onreadystatechange = () => {
            if (xhr.readyState === 4 && xhr.status === 200) {
                this[variable] = xhr.responseText.replace(/@font-face{[^}]+}/, "");
                callback();
            }
        };
        xhr.open("GET", url);
        xhr.send();
    },
    getThemeCluster: function (theme) {
        const tintColor = (color, tint) => {
            let red = parseInt(color.slice(0, 2), 16);
            let green = parseInt(color.slice(2, 4), 16);
            let blue = parseInt(color.slice(4, 6), 16);
            if (tint === 0) {
                return [red, green, blue].join(",");
            } else {
                red += Math.round(tint * (255 - red));
                green += Math.round(tint * (255 - green));
                blue += Math.round(tint * (255 - blue));

                red = red.toString(16);
                green = green.toString(16);
                blue = blue.toString(16);

                return `#${red}${green}${blue}`;
            }
        };

        const shadeColor = (color, shade) => {
            let red = parseInt(color.slice(0, 2), 16);
            let green = parseInt(color.slice(2, 4), 16);
            let blue = parseInt(color.slice(4, 6), 16);

            red = Math.round((1 - shade) * red);
            green = Math.round((1 - shade) * green);
            blue = Math.round((1 - shade) * blue);

            red = red.toString(16);
            green = green.toString(16);
            blue = blue.toString(16);

            return `#${red}${green}${blue}`;
        };

        const clusters = [theme];
        for (let i = 0; i <= 9; i++) {
            clusters.push(tintColor(theme, Number((i / 10).toFixed(2))));
        }
        clusters.push(shadeColor(theme, 0.1));
        return clusters;
    },
    createColor: function (val, oldVal) {
        if (typeof val !== "string") return;
        const themeCluster = this.getThemeCluster(val.replace("#", ""));
        const originalCluster = this.getThemeCluster(oldVal.replace("#", ""));
        const getHandler = (variable, id) => {
            return () => {
                const originalCluster = this.getThemeCluster(
                    ORIGINAL_THEME.replace("#", "")
                );
                const newStyle = this.updateStyle(
                    this[variable],
                    originalCluster,
                    themeCluster
                );

                let styleTag = document.getElementById(id);
                if (!styleTag) {
                    styleTag = document.createElement("style");
                    styleTag.setAttribute("id", id);
                    document.head.appendChild(styleTag);
                }
                styleTag.innerText = newStyle;
            };
        };
        const chalkHandler = getHandler("chalk", "chalk-style");
        if (!this.chalk) {
            const url = `https://unpkg.com/element-ui@${version}/lib/theme-chalk/index.css`;
            this.getCSSString(url, chalkHandler, "chalk");
        } else {
            chalkHandler();
        }
        const styles = [].slice
            .call(document.querySelectorAll(".--color-primary"))
            .filter((style) => {
                const text = style.innerText;
                return (
                    new RegExp(oldVal, "i").test(text) && !/Chalk Variables/.test(text)
                );
            });
        styles.forEach((style) => {
            const { innerText } = style;
            if (typeof innerText !== "string") return;
            style.innerText =this.updateStyle(
                innerText,
                originalCluster,
                themeCluster
            );
        });
    },
    lightenDarkenColor: function (col, amt) {
        var usePound = false;
        if (col[0] == "#") {
            col = col.slice(1);
            usePound = true;
        }
        var num = parseInt(col, 16);
        var r = (num >> 16) + amt;
        if (r > 255) r = 255;
        else if (r < 0) r = 0;
        var b = ((num >> 8) & 0x00ff) + amt;
        if (b > 255) b = 255;
        else if (b < 0) b = 0;
        var g = (num & 0x0000ff) + amt;
        if (g > 255) g = 255;
        else if (g < 0) g = 0;
        return (usePound ? "#" : "") + (g | (b << 8) | (r << 16)).toString(16);
    },
    changeColors: function (backgroundColor) {//,第二个参数 fontColor="#333"
        //淡色
        let lightColor = this.lightenDarkenColor(
            backgroundColor,
            colorAngle
        );
        //深色
        let sColor = this.lightenDarkenColor(
            backgroundColor,
            colorAngleS
        );
        console.log(backgroundColor,lightColor,sColor)
        let arr=document.getElementsByTagName('body')[0];
        arr.style.setProperty('--testBackgroundColor', backgroundColor)
        arr.style.setProperty('--testBackgroundColorRGB', lightColor);
        arr.style.setProperty('--testBackgroundColorRGBS', sColor);
        sessionStorage["themeColor"] = backgroundColor;
        sessionStorage["themeColorRGB"] = lightColor;
        sessionStorage["themeColorRGBS"] = sColor;
        this.createColor(backgroundColor, sessionStorage["themeColor"]);
    }
}
